1. Field of the Invention
The present invention generally relates to a method for fabricating a thin film transistor (TFT), in particular, to a method for fabricating a TFT using a metal oxide as an active layer.
2. Description of Related Art
In recent years, due to the progress of the semiconductor process technology, TFTs are fabricated more easily and quickly. The TFTs are widely applied to computer chips, mobile phone chips, TFT liquid crystal displays (TFT LCDs), or other electronic products. For example, for the TFT LCDs, the TFTs are used as charging or discharging switches of a storage capacitor.
Generally speaking, according to material of the active layer, the TFT may be divided into amorphous silicon TFT and polycrystalline silicon TFT. However, in response to the increasing demands for the LCDs in the market, more efforts are put into the research and development of new TFT technique. The TFTs adopting the metal oxide, for example, ZnO, as the active layer have been developed, and the electrical characteristics thereof catch up with the amorphous silicon TFTs, and the element representation is good.
However, for example, for the TFT using ZnO as the active layer, in the subsequent process of forming a source and a drain, ZnO is easily damaged by, for example, plasma, etchant, stripper, and other materials, such that the active layer of the thin film characteristics would be changed, thereby influencing the element characteristics of the TFTs.